Ultrasonic borehole classification method
AssigneeSchlumberger Technology Corporation
InventorsMizuki Yajima, Naoki Sakiyama, Hiroaki Yamamoto, Kong Hauw Sarwa Bakti Tan
Life of this patent
Estimating the term…
Abstract
A method for classifying a subterranean formation includes rotating an ultrasonic logging tool in a borehole penetrating a formation. The ultrasonic logging tool includes an ultrasonic transducer and an array of spaced apart ultrasonic receivers deployed on a logging tool body. The ultrasonic logging tool measures an azimuthal shear slowness image and an azimuthal compressional slowness image while rotating in the borehole. The images are evaluated to classify the homogeneity/heterogeneity and isotropy/anisotropy of the formation.
Claims19
A method for classifying a subterranean formation, the method comprising:
- rotating an ultrasonic logging tool in a borehole penetrating a formation, the ultrasonic logging tool including an ultrasonic transducer and an array of spaced apart ultrasonic receivers deployed on a logging tool body;
- measuring an ultrasonic pulse-echo amplitude image, an azimuthal shear slowness image, and an azimuthal compressional slowness image while rotating the ultrasonic logging tool in the borehole;
- and
- evaluating the pulse-echo amplitude image, the azimuthal shear slowness image, and the azimuthal compressional slowness image to classify the formation as (i) homogeneous or heterogeneous, (ii) stress-induced anisotropic or not stress-induced anisotropic, and (iii) intrinsic anisotropic or not intrinsic anisotropic.
An ultrasonic logging tool comprising:
- a logging tool body;
- an ultrasonic transducer deployed in the logging tool body;
- an array of spaced apart ultrasonic receivers deployed in the logging tool body;
- and
- a controller deployed in the logging tool body and configured to:
- measure an ultrasonic pulse-echo amplitude image, an azimuthal shear slowness image, and an azimuthal compressional slowness image while the ultrasonic logging tool rotates in a borehole penetrating a formation;
- and
- evaluate the ultrasonic pulse-echo amplitude image, the azimuthal shear slowness image, and the azimuthal compressional slowness image to classify the formation as (i) homogeneous or heterogeneous, (ii) stress-induced anisotropic or not stress-induced anisotropic, and (iii) intrinsic anisotropic or not intrinsic anisotropic.
A method for classifying a subterranean formation, the method comprising:
- rotating an ultrasonic logging tool in a borehole, the ultrasonic logging tool including an ultrasonic transducer and an array of spaced apart ultrasonic receivers deployed on a logging tool body;
- measuring an azimuthal shear slowness image and an azimuthal compressional slowness image while the ultrasonic logging tool rotates in the borehole;
- evaluating a periodic component of the azimuthal shear slowness image to classify the formation as isotropic or anisotropic;
- and
- evaluating a periodic component of the azimuthal compressional slowness image to classify the formation as intrinsic anisotropic or stress-induced anisotropic.
Dependencies are inferred from the claim text.